<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>绝对定位</title>
    <style>
        div{
            height:200px;
            width:200px;
            background: peru;
        }
        .test{
            background: red;
            position:absolute;
            left:300px;
        }
    </style>
</head>
<body>
<!--绝对定位：脱离文档流。参照物：浏览器/已定位的父元素-->
<div class="test"></div>
<div class="tar">参照物</div>
</body>
</html>